| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide techniques for preventing variation (ringing) caused by changing an output waveform because of a bias voltage of an external optical modulator, therefore, changing an average refractive index in steps to control to an optimal point such as in initiation and chirp switching. <P>SOLUTION: An optical transmitter having an external modulator for modulating a driving signal on which a low-frequency signal is superposed performs: supplying the driving signal to the external modulator; monitoring the modulated light to bias the external modulator for maintaining the driving signal at a predetermined level; and controlling the intensity of the light so as to compensate for refractive index variation of the external modulator which is caused by variation of the bias. <P>COPYRIGHT: (C)2009,JPO&INPIT |
